Reactive disazo dyestuffs



United States Patent Claims. (Cl. 260184) This application is a divisionof our application Serial No. 194,652, filed May 14, 1962, and nowabandoned.

The present invention relates to anew class of reactive dyestuffs, i.e.of dyestuffs able to form chemical bonds with a fiber during the dyeingof such fiber, to thereby produce dyes which are particularly stable towet treatments.

Several classes of dyestuffs are already known wherein reactive groupsare present.

In particular, dyestuffs are known which comprise one of the followingreactive groups: monochlorotriazinic, dichlorotriazinic,chloropyrimidino, betachloropropionamido, vinylsulphonic group.

The conditions for the application of such dyestuffs vary owing to thereactivity of the particular group which is present.

There has now been found a new class of reactive dyestuifs which arecompletely different from those previously known. This class ischaracterized by the presence, as a reactive group, of a phenyl radicalcontaining at least one active halogen atom (preferably Cl and/or Br)and one or more nucleophilic substituents (preferably --NO and/ or SOH).

Particularly interesting'results have been obtained by introducing theradical into the structure of a dye.

This radical renders dyes containing it particularly suit able fordyeing cellulosic fibers the hydroxyl groups of which react with theactive halogen atom.

The dyestuffs of the present invention are preparedby reacting asuitable benzene derivative with aromatic amines containing earboxyl orsulphonic groups, or with aromatic diamines.

Among the products obtained starting from 1,3 dichloro 4,6dinitrobenzene are included those products having the followingstructure:

oar-QNn-a-ma,

3,301,847 Patented Jan. 31, 1967 "ice wherein R has the previouslyindicated meaning, and wherein R is the residue of the amino or phenoliccoupling agent, which residue may contain substituents, such as forexample N0 SO H, Cl, and, may or may not contain solubilizing groups.

If R and R contain OH groups in the ortho position with respect to thediazo group, metallization may be performed between these two -OHgroups.

When R contains an amino group which in turn can be diazotized orcoupled, compounds having a polyazo structure are obtained, whichcompounds exhibit good dyeing characteristics. Such polyazo compoundsmay be represented by the formula Br) and one or more nucleophilicsubstituents (preferably NO and/ or SO H) and more precisely polyazo dyestuffs comprised in the Formula III.

. All these dyestuffs are characterized by the presence the reactiveradical which makes them able to chemically bind themselves to treatedfibers and particularly to cellulosic fibers.

The dyeing process with the aid of said dyestuffs is preferably carriedout at a pH of from about 10 to 11 and gives shades having a very goodfastness to wettreatment's.

The-following examples will further illustrate this in-.

vention.

Example 1 1 mole of 1,3-dichloro-4,6-dinitrobenzene is reacted inalcoholic solution together with 1 mole of p-phenylenediamine.

After boiling the mixture for a short time, a crystalline precipitate isobtained which is purified by crystallization from chloro-benzene.

The product thus obtained has the following structure:

M.P.=1923 0. red shade 1 mole of the above mentioned product (obtainedfrom the condensation of 1,3-dichloro-4,6-dinitrobenzene withp-phenylene-diamine) is batched with 34 moles of dilute HCl.

To the yellow suspension thus obtained is added an aqueous solution ofsodium nitrite at room temperature to form a diazonium salt.

A solution of the azo compound, obtained by coupling the diazo ofp-nitro-aniline with H acid in an acidic medium, is treated with theforegoing diazo of the condensation product obtained from1,3-dichloro-4,6-dinitrobenzene and p-phenylenediamine.

The treatment is carried out in alkaline medium, with stirring for 8-12hours at room temperature. A

The mixture is salted with ammonium sulphate. A bisazo compound isobtained which dyes cotton in washfast green-blue shades.

Examples 2 and 3 The following two formulas indicate other reactivedyestuffs of the present invention, which dyestuffs are obtained in amanner analogous to that indicated in the preceding example.

( lTTOz OzNQITII-I 11 01 N=N N=N OH HOaS- soai 1' 00011 2 N02 on I Jsoar 00011 Example 4 Any of the dyestuffs described in the precedingexamples is used for dyeing cotton according to the following method:

Concentration, dyestuflY/fiber: 2% Bath ratio:

The fiber is dipped into the dye solution at room temperature in orderto make possible the inhibition. After about minutes the addition ofsodium sulphate as -25% aqueous solution and in the ratio of 10-15 g./l.on the dyeing bath is commenced.

The addition is carried out slowly (during the dyeing process) in orderto avoid precipitation of the dyestuif.

Caustic soda, as 2.5% solution, is added in order to maintain the pH ata value of from about 10 to 11.

The bath is heated at 70-80 C. and this temperature is maintainedconstant for from 2 to 2% hours.

1 The dyed material is wrung, washed with water, and is then washed witha 2.5% soap solution (temperature: 90 C.; time: 1030 minutes). Finallythe material is washed with water. The material thus treated, even whensubjected to a further prolonged treatment with soap, does not lose dye.Fast dyeings are realized.

Example 5 The dyeing bath is prepared as described in the foregoingexample; the yarn is impregnated in the bath and is dried at about 110C.

wherein R, R and'R are each selected from the group consisting ofphenyl, naphthyl, substituted phenyl and substituted naphthyl radicals,the substituents on said sub? stituted radicals being selected from the:group consisting of OH, COOH, SOgH, -NO -NH and Cl. 2. The'dyestuif ofclaim 1 wherein said substituents on said R radicals are selected fromthe group consisting of OH, COOH and SO H.

3. A reactive dyestuff having the structure NO: OH NH:

soar

4. A reactive dyestuff having the structure OzN NH O H or N=N N=N F 0 HHOaS- SOaH -000H 5. A reactive dyestufi having the structure I NO: =N N=OOH OzN NH SOzH 00011 No references cited.

CHARLES B. PARKER, Primary Examiner. F. D. HIGEL, Assistant Examiner.

1. A REACTIVE DYESTUFF HAVING THE FORMULA